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//* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// This header file defines the storage types of the actual safebrowsing
// chunk data, which may be either 32-bit hashes or complete 256-bit hashes.
// Chunk numbers are represented in ChunkSet.h.
#ifndef SBEntries_h__
#define SBEntries_h__
#include "nsTArray.h"
#include "nsString.h"
#include "nsICryptoHash.h"
#include "nsNetUtil.h"
#include "nsIOutputStream.h"
#include "nsClassHashtable.h"
#include "nsComponentManagerUtils.h"
#include "nsTHashMap.h"
#include "plbase64.h"
namespace mozilla {
namespace safebrowsing {
#define PREFIX_SIZE 4
#define COMPLETE_SIZE 32
// This is the struct that contains 4-byte hash prefixes.
template <uint32_t S, class Comparator>
struct SafebrowsingHash {
static_assert(S >= 4, "The SafebrowsingHash should be at least 4 bytes.");
static const uint32_t sHashSize = S;
typedef SafebrowsingHash<S, Comparator> self_type;
uint8_t buf[S];
nsresult FromPlaintext(const nsACString& aPlainText) {
// From the protocol doc:
// Each entry in the chunk is composed
// of the SHA 256 hash of a suffix/prefix expression.
nsresult rv;
nsCOMPtr<nsICryptoHash> hash =
do_CreateInstance(NS_CRYPTO_HASH_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = hash->Init(nsICryptoHash::SHA256);
NS_ENSURE_SUCCESS(rv, rv);
rv = hash->Update(
reinterpret_cast<const uint8_t*>(aPlainText.BeginReading()),
aPlainText.Length());
NS_ENSURE_SUCCESS(rv, rv);
nsAutoCString hashed;
rv = hash->Finish(false, hashed);
NS_ENSURE_SUCCESS(rv, rv);
NS_ASSERTION(hashed.Length() >= sHashSize,
"not enough characters in the hash");
memcpy(buf, hashed.BeginReading(), sHashSize);
return NS_OK;
}
void Assign(const nsACString& aStr) {
NS_ASSERTION(aStr.Length() >= sHashSize,
"string must be at least sHashSize characters long");
memcpy(buf, aStr.BeginReading(), sHashSize);
}
int Compare(const self_type& aOther) const {
return Comparator::Compare(buf, aOther.buf);
}
bool operator==(const self_type& aOther) const {
return Comparator::Compare(buf, aOther.buf) == 0;
}
bool operator!=(const self_type& aOther) const {
return Comparator::Compare(buf, aOther.buf) != 0;
}
bool operator<(const self_type& aOther) const {
return Comparator::Compare(buf, aOther.buf) < 0;
}
void ToString(nsACString& aStr) const {
// Base64 represents 6-bits data as 8-bits output.
uint32_t len = ((sHashSize + 2) / 3) * 4;
aStr.SetLength(len);
PL_Base64Encode((char*)buf, sHashSize, aStr.BeginWriting());
MOZ_ASSERT(aStr.BeginReading()[len] == '\0');
}
nsCString ToString() const {
nsAutoCString str;
ToString(str);
return std::move(str);
}
void ToHexString(nsACString& aStr) const {
static const char* const lut = "0123456789ABCDEF";
// 32 bytes is the longest hash
size_t len = 32;
aStr.SetCapacity(2 * len);
for (size_t i = 0; i < len; ++i) {
const char c = static_cast<char>(buf[i]);
aStr.Append(lut[(c >> 4) & 0x0F]);
aStr.Append(lut[c & 15]);
}
}
uint32_t ToUint32() const {
uint32_t n;
memcpy(&n, buf, sizeof(n));
return n;
}
void FromUint32(uint32_t aHash) { memcpy(buf, &aHash, sizeof(aHash)); }
};
class PrefixComparator {
public:
static int Compare(const uint8_t* a, const uint8_t* b) {
uint32_t first;
memcpy(&first, a, sizeof(uint32_t));
uint32_t second;
memcpy(&second, b, sizeof(uint32_t));
if (first > second) {
return 1;
} else if (first == second) {
return 0;
} else {
return -1;
}
}
};
// Use this for 4-byte hashes
typedef SafebrowsingHash<PREFIX_SIZE, PrefixComparator> Prefix;
typedef nsTArray<Prefix> PrefixArray;
class CompletionComparator {
public:
static int Compare(const uint8_t* a, const uint8_t* b) {
return memcmp(a, b, COMPLETE_SIZE);
}
};
// Use this for 32-byte hashes
typedef SafebrowsingHash<COMPLETE_SIZE, CompletionComparator> Completion;
typedef nsTArray<Completion> CompletionArray;
struct AddPrefix {
// The truncated hash.
Prefix prefix;
// The chunk number to which it belongs.
uint32_t addChunk;
AddPrefix() : addChunk(0) {}
// Returns the chunk number.
uint32_t Chunk() const { return addChunk; }
const Prefix& PrefixHash() const { return prefix; }
template <class T>
int Compare(const T& other) const {
int cmp = prefix.Compare(other.PrefixHash());
if (cmp != 0) {
return cmp;
}
return addChunk - other.addChunk;
}
};
struct AddComplete {
Completion complete;
uint32_t addChunk;
AddComplete() : addChunk(0) {}
uint32_t Chunk() const { return addChunk; }
// The 4-byte prefix of the sha256 hash.
uint32_t ToUint32() const { return complete.ToUint32(); }
// The 32-byte sha256 hash.
const Completion& CompleteHash() const { return complete; }
template <class T>
int Compare(const T& other) const {
int cmp = complete.Compare(other.CompleteHash());
if (cmp != 0) {
return cmp;
}
return addChunk - other.addChunk;
}
bool operator!=(const AddComplete& aOther) const {
if (addChunk != aOther.addChunk) {
return true;
}
return complete != aOther.complete;
}
};
struct SubPrefix {
// The hash to subtract.
Prefix prefix;
// The chunk number of the add chunk to which the hash belonged.
uint32_t addChunk;
// The chunk number of this sub chunk.
uint32_t subChunk;
SubPrefix() : addChunk(0), subChunk(0) {}
uint32_t Chunk() const { return subChunk; }
uint32_t AddChunk() const { return addChunk; }
const Prefix& PrefixHash() const { return prefix; }
template <class T>
// Returns 0 if and only if the chunks are the same in every way.
int Compare(const T& aOther) const {
int cmp = prefix.Compare(aOther.PrefixHash());
if (cmp != 0) return cmp;
if (addChunk != aOther.addChunk) return addChunk - aOther.addChunk;
return subChunk - aOther.subChunk;
}
template <class T>
int CompareAlt(const T& aOther) const {
Prefix other;
other.FromUint32(aOther.ToUint32());
int cmp = prefix.Compare(other);
if (cmp != 0) return cmp;
return addChunk - aOther.addChunk;
}
};
struct SubComplete {
Completion complete;
uint32_t addChunk;
uint32_t subChunk;
SubComplete() : addChunk(0), subChunk(0) {}
uint32_t Chunk() const { return subChunk; }
uint32_t AddChunk() const { return addChunk; }
const Completion& CompleteHash() const { return complete; }
// The 4-byte prefix of the sha256 hash.
uint32_t ToUint32() const { return complete.ToUint32(); }
int Compare(const SubComplete& aOther) const {
int cmp = complete.Compare(aOther.complete);
if (cmp != 0) return cmp;
if (addChunk != aOther.addChunk) return addChunk - aOther.addChunk;
return subChunk - aOther.subChunk;
}
};
typedef FallibleTArray<AddPrefix> AddPrefixArray;
typedef FallibleTArray<AddComplete> AddCompleteArray;
typedef FallibleTArray<SubPrefix> SubPrefixArray;
typedef FallibleTArray<SubComplete> SubCompleteArray;
typedef FallibleTArray<Prefix> MissPrefixArray;
/**
* Compares chunks by their add chunk, then their prefix.
*/
template <class T>
class EntryCompare {
public:
typedef T elem_type;
static int Compare(const void* e1, const void* e2) {
const elem_type* a = static_cast<const elem_type*>(e1);
const elem_type* b = static_cast<const elem_type*>(e2);
return a->Compare(*b);
}
};
/**
* Sort an array of store entries. nsTArray::Sort uses Equal/LessThan
* to sort, this does a single Compare so it's a bit quicker over the
* large sorts we do.
*/
template <class T, class Alloc>
void EntrySort(nsTArray_Impl<T, Alloc>& aArray) {
qsort(aArray.Elements(), aArray.Length(), sizeof(T),
EntryCompare<T>::Compare);
}
template <class T, class Alloc>
nsresult ReadTArray(nsIInputStream* aStream, nsTArray_Impl<T, Alloc>* aArray,
uint32_t aNumElements) {
if (!aArray->SetLength(aNumElements, fallible)) return NS_ERROR_OUT_OF_MEMORY;
void* buffer = aArray->Elements();
nsresult rv =
NS_ReadInputStreamToBuffer(aStream, &buffer, (aNumElements * sizeof(T)));
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
template <class T, class Alloc>
nsresult WriteTArray(nsIOutputStream* aStream,
nsTArray_Impl<T, Alloc>& aArray) {
uint32_t written;
return aStream->Write(reinterpret_cast<char*>(aArray.Elements()),
aArray.Length() * sizeof(T), &written);
}
typedef nsClassHashtable<nsUint32HashKey, nsCString> PrefixStringMap;
typedef nsTHashMap<nsCStringHashKey, int64_t> TableFreshnessMap;
typedef nsCStringHashKey FullHashString;
typedef nsTHashMap<FullHashString, int64_t> FullHashExpiryCache;
struct CachedFullHashResponse {
int64_t negativeCacheExpirySec;
// Map contains all matches found in Fullhash response, this field might be
// empty.
FullHashExpiryCache fullHashes;
CachedFullHashResponse& operator=(const CachedFullHashResponse& aOther) {
negativeCacheExpirySec = aOther.negativeCacheExpirySec;
fullHashes = aOther.fullHashes.Clone();
return *this;
}
bool operator==(const CachedFullHashResponse& aOther) const {
if (negativeCacheExpirySec != aOther.negativeCacheExpirySec ||
fullHashes.Count() != aOther.fullHashes.Count()) {
return false;
}
for (const auto& entry : fullHashes) {
if (entry.GetData() != aOther.fullHashes.Get(entry.GetKey())) {
return false;
}
}
return true;
}
};
typedef nsClassHashtable<nsUint32HashKey, CachedFullHashResponse>
FullHashResponseMap;
template <class T>
void CopyClassHashTable(const T& aSource, T& aDestination) {
for (const auto& entry : aSource) {
auto value = aDestination.GetOrInsertNew(entry.GetKey());
*value = *(entry.GetData());
}
}
} // namespace safebrowsing
} // namespace mozilla
#endif // SBEntries_h__